Ramaria ochraceovirens – synoniem of Ramaria abietina
Resupinatus cyphelliformis – synoniem of Hohenbuehelia cyphelliformis
Resupinatus trichotis – synoniem of Resupinatus applicatus
Rhodocybe truncata – synoniem of Rhodocybe gemina
Rickenella setipes – synoniem of Rickenella swartzii
Rigidoporus sanguinolentus – synoniem of Physisporinus sanguinolentus
Rigidoporus vitreus – synoniem of Physisporinus vitreus
Rozites caperata – synoniem of Rozites caperatus
Russula atrorubens – synoniem of Russula olivaceoviolascens
Russula flava – synoniem of Russula claroflava
Russula laccata – synoniem of Russula olivaceoviolascens
Russula rosacea – synoniem of Russula rosea
Russula sardonia – synoniem of Russula drimeia
Rutstroemia firma – synoniem of Poculum firmum